-#define ClearScreen() ST->ConOut->ClearScreen(ST->ConOut)
-#define SetTextAttr(a) ST->ConOut->SetAttribute(ST->ConOut, a)
+#define ClearScreen() uefi_call_wrapper(ST->ConOut->ClearScreen, 1, ST->ConOut)
+#define SetTextAttr(a) uefi_call_wrapper(ST->ConOut->SetAttribute, 2, ST->ConOut, a)